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One of the most promising tools in the strategy to reduce New Zealand’s greenhousegas emissions from agriculture is making steady progress towards commercialisation.

Internationally, New Zealand has made a commitment to lower its greenhouse gasemissions to agreed targets. The two problem gases for New Zealand are methane andnitrous oxide.

Methane inhibitors have the potential to reduce methane production by around 30 percent, so their widespread adoption by farmers would make a significant dent inreaching the country’s reduction targets. However, with New Zealand livestock eatinggrass 90 per cent of the time, there are challenges to realising this potential, includinghow the inhibitor would be given to animals and ensuring the economics stack up.

To help people understand of the complexities around reducing agriculturalgreenhouse gas emissions, the farmer-supported Pastoral Greenhouse Gas ResearchConsortium (PGgRc) and New Zealand Agricultural Greenhouse Gas ResearchCentre (NZAGRC) have developed a series of fact sheets. The most recent focuses onmethane inhibitors.

How is methane produced?The rumen is essentially a fermentation vat. It contains microbes that play a role infermentation. One of those microbes is methanogen. However, methanogens are notessential to the animal – in fact, they are opportunists. They use hydrogen gas, a by-product of fermentation, and combine it with carbon dioxide to produce methane andwater. The methane is then released into the atmosphere when the animal belches.

How does a methane inhibitor work?Scientists have identified chemical compounds that simply stop the methanogensfrom working, shutting down the process of methane production.A Swiss company has developed an inhibitor that works in a feedlot system, where itcan be mixed with feed and consumed continuously. However, this isn’t practical inNew Zealand’s pasture-based system. A practical delivery mechanism is therefore oneof the challenges. Options, such as bolus capsules, are being investigated.

How long until farmers can buy inhibitors?Conversations with potential commercial partners are underway. However, testing torule out any impact on animals’ health, welfare and productivity needs to be carriedout, as well as ensuring there are no residue or food safety concerns.

All going to plan, commercial release is expected sometime after 2023. Significantly,the technology should be applicable internationally.